Venturing into the death zone on Mount Everest

British climber David Sharp had made two prior attempts to climb Everest, losing parts of two toes to frostbite. He vowed his third trip would be his last

By Allen Breed and Binaj Gurubacharya / AP , KATHMANDU

on the threshold

As far as Stangl could tell, Sharp was down to just one cylinder. But Sharp knew the mountain was littered with partial bottles that he could use.

By May 11, Sharp had reached Camp One at the North Col again. He popped his head out of his green tent to offer congratulations to Watson and partner Gheorge Dijmarescu as they descended from what was Dijmarescu's eighth successful summit and Watson's second.

Over the next three days, Sharp clawed his way back into the Death Zone, threshold of the summit.

He was at about 8,352m shortly after 1am on the May 14, when Colorado climber Bill Crouse and his team of a dozen clients and Sherpas spotted him on their ascent at a diagonally rising traverse known as the Exit Cracks.

Looking tired, Sharp sat in the falling snow, disconnected from the fixed line to let other, faster climbers pass. In the darkness, the climbers exchanged waves.

Crouse, working as a guide for noted New Zealand climber Russell Brice, reached the summit and keyed his two-way radio as multicolored Buddhist prayer flags flapped in a bitterly cold wind.

"How much time do we have?" Crouse asked Brice, who had been watching the ascent through a telescope from camp at the North Col.

"No more than 20 minutes," the leader said.

Descending, Crouse and his team reached the top of the Third Step, roughly 148m from the summit, around 11:20am, when the guide noticed Sharp again at its base -- off to the side, out of the blowing wind.

He was clipped to the fixed line, and Crouse's party unclipped and re-clipped to get around him.

"Watch out," Crouse warned Sharp, but nothing else was said.

About an hour and 20 minutes later, at the Second Step, Crouse looked back. The man his team had gone around had moved higher, but barely -- just 90m or so. He appeared to be the last one up the mountain.

"That guy's going up pretty late in the day today," Crouse said to a companion.

Sharp had already climbed higher than he'd ever been before. At this altitude, he was taking several breaths for each step, but the summit awaited, so close now.